Congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders characterized by impaired cortisol synthesis. It results from the deficiency of one of the five enzymes required for the synthesis of cortisol in the adrenal cortex. Most of these disorders involve excessive or deficient production of hormones such as glucocorticoids, mineralocorticoids, or sex steroids, and can alter development of primary or secondary sex characteristics in some affected infants, children, or adults. It is one of the most common autosomal recessive disorders in humans.

Types

CAH can occur in various forms. The clinical presentation of each form is different and depends to a large extent on the underlying enzyme defect, its precursor retention, and deficient products. Classical forms appear in infancy and nonclassical forms appear in late childhood. The presentation in patients with classical CAH can be further subdivided into two forms: salt-wasting and simple-virilizing depending on whether mineralocorticoid deficiency is present or absent, respectively. This subtyping is often not clinically meaningful, though, because all patients lose salt to some degree, and clinical presentations may overlap.

Classical

Salt-wasting

In 75% of cases of severe enzyme deficiency, insufficient aldosterone production can lead to salt wasting, failure to thrive, and potentially fatal hypovolemia and shock.